The present invention relates to a novel organic coating to be used on metal surfaces as a protective barrier against corrosion and a method of preparing a paint-like material to be applied to a metal surface to form said coating.
Several attempts have been made to obtain anticorrosive coatings for pipes and tanks from high viscosity components present in natural hydrocarbons. An example of this is the commercial epoxy tar coating systems, whose use dates back to the 1950's. U.S. Pat. No. 2,765,288 to Pittsburgh Coke and Chemical Co. describes one such epoxy tar coating system. In general, these coatings are formulated from coal tar, epoxy resin, solvents, additives and curing agents of the amine or polyamide types. The coatings generally constitute an effective physical and mechanical barrier. Some of them may be used jointly with cathodic protection systems.
U.S. Pat. Nos. 4,162,998 and 4,499,215 display other coatings in which a modified asphalt is used with an epoxy resin. These coatings feature good impermeability and rust-resistance and can be obtained from economical raw materials. However, in order for the asphalt to be resin-compatible, its chemical nature must be modified by means of complex chemical processes. In Japanese patent application J9075664-A and J77003679-B, a third component consisting of coal dust is added to the base formulation, thus resulting in a coating with properties similar to the ones above-mentioned.
It is an object of the present invention to provide a coating which can be used on metal surfaces as a protective barrier against corrosion.
It is further object of the present invention to provide an organic coating as above which is competitive with commercial tar coatings.
It is yet a further object of the present invention to provide a coating as above which may be used in a wide range of applications and may be easily applied.
It is still another object of the present invention to provide a coating as above with highly enhanced hardness and abrasion-resistance properties and a method of preparing a paint-like material for forming said coating.
Still further objects and advantages will become apparent from the following description and drawings.